The visitor, by scrolling with a finger on the display of his smartphone connected to a specific wireless network, generates and moves the "angelùddhi" which traces sound trails in the musical texture of the digital oscillators diffused by the speakers and visual streaks on the surface of the watercolours. One or more people can act simultaneously from their smartphones, determining univocal or uncertain and contradictory behavior of the "angelùddhi", a metaphor for the relationships between the individual and the group.